1. Field of the Invention
In general, the invention relates to electrical safety devices, and more particularly, to a caution and warning barrier system that is used to prevent personnel from entering areas in which electrical arcing is likely.
2. Description of Related Art
Electrical arcs result from the release of electrical energy through the air when high voltage bridges a gap between conductors. Electrical arcs can occur naturally, e.g., lightning, but they are also common with electrical machinery. These electrical discharges are highly unpredictable and vary in occurrence, energy, path, and duration. Electrical faults resulting in electrical arcs give off thermal radiation and bright, intense light that can cause burns to the body. High-voltage arcs can also produce a considerable pressure wave by rapidly heating the air and producing a blast that can send molten metal droplets from melted copper and aluminum components in electrical equipment great distances at extremely high velocities. In addition to direct personal injury from these hot metals, arc blasts can throw a worker against nearby objects, causing secondary injuries, such as blunt force trauma, cuts, and abrasions. The impulse sound wave near the unprotected ear can also result in temporary or permanent traumatic hearing loss. Electrical arcs can also cause non-contact flash burns without accompanying electric shock, in which case the person receiving the arc burn never actually contacts an energized electrical conductor.
The hazards of non-contact electric arc flashes are present at most industrial workplaces and are an everyday occurrence. Due to the nature and attitudes of industrial work, may workers experience electrical arcs in varying degrees, but do not report them because they are not, or do not perceive themselves to be, injured. Non-contact arcing incidents can result from human error as well as from equipment malfunctions and accidents; however, arcs are not always predictable or traceable to a particular error, malfunction, or circumstance. Sometimes, they simply occur—which is what makes them so dangerous.
Standards for protecting workers generally focus on technical skills, instrumentation, safe operating procedures, and personal protective equipment. Protective equipment, including clothing, is one way of preventing arc flash injury. Good equipment design, proper maintenance, and good training can also reduce the risk of injury. However, even with standards, protective equipment, and other conventional measures, arcing incidents still occur, and still take a toll.